Allied Air Enterprises 4AC18LT - Manual (Page 15)

506469-01 Issue 1008 Page 15 of 24
6. Compare the approach value with those shown in Table
7. If the values do not agree with those provided in Table 7,
add refrigerant to lower the approach temperature or recover
refrigerant from the system to increase the approach
temperature.
Check Charge Using Normal Operating Pressures
Use Table 8 to perform maintenance checks. Table 8 is not
a procedure for charging the system. Minor variations in
these pressures may be due to differences in installations.
Significant deviations could mean that the system is not
properly charged or that a problem exists with some
component in the system.
=
_
Outdoor Ambient Temperature °F
Liquid Line Temperature °F
Approach Temperature °F
°
°
°
=
_
Liquid Line Temperature °F
Saturation Temperature °F
Subcooling Value °F
°
°
°
Table 7
Subcooling Values
Table 8
Approach Values for TXV Systems
Approach value is the liquid line temperature minus
the outdoor ambient temperature (± 1°F).
Note: For best results, use the same digital
thermometer to check both outdoor ambient and
liquid temperatures.
Table 6
T e m p .
(F
P re s s u re
P s ig
T e m p .
(F
P re s s u re
P s ig
T e m p .
(F
P re s s u re
P s ig
3 2 1 0 0 .8 7 4 2 1 4 .0 1 1 6 3 9 6 .0
3 3 1 0 2 .9 7 5 2 1 7 .4 1 1 7 4 0 1 .3
3 4 1 0 5 .0 7 6 2 2 0 .9 1 1 8 4 0 6 .7
3 5 1 0 7 .1 7 7 2 2 4 .4 1 1 9 4 1 2 .2
3 6 1 0 9 .2 7 8 2 2 8 .0 1 2 0 4 1 7 .7
3 7 1 1 1 .4 7 9 2 3 1 .6 1 2 1 4 2 3 .2
3 8 1 1 3 .6 8 0 2 3 5 .3 1 2 2 4 2 8 .8
3 9 1 1 5 .8 8 1 2 3 9 .0 1 2 3 4 3 4 .5
4 0 1 1 8 .0 8 2 2 4 2 .7 1 2 4 4 4 0 .2
4 1 1 2 0 .3 8 3 2 4 6 .5 1 2 5 4 4 5 .9
4 2 1 2 2 .6 8 4 2 5 0 .3 1 2 6 4 5 1 .8
4 3 1 2 5 .0 8 5 2 5 4 .1 1 2 7 4 5 7 .6
4 4 1 2 7 .3 8 6 2 5 8 .0 1 2 8 4 6 3 .5
4 5 1 2 9 .7 8 7 2 6 2 .0 1 2 9 4 6 9 .5
4 6 1 3 2 .2 8 8 2 6 6 .0 1 3 0 4 7 5 .6
4 7 1 3 4 .6 8 9 2 7 0 .0 1 3 1 4 8 1 .6
4 8 1 3 7 .1 9 0 2 7 4 .1 1 3 2 4 8 7 .8
4 9 1 3 9 .6 9 1 2 7 8 .2 1 3 3 4 9 4 .0
5 0 1 4 2 .2 9 2 2 8 2 .3 1 3 4 5 0 0 .2
5 1 1 4 4 .8 9 3 2 8 6 .5 1 3 5 5 0 6 .5
5 2 1 4 7 .4 9 4 2 9 0 .3 1 3 6 5 1 2 .9
5 3 1 5 0 .1 9 5 2 9 5 .1 1 3 7 5 1 9 .3
5 4 1 5 2 .8 9 6 2 9 9 .4 1 3 8 5 2 5 .8
5 5 1 5 5 .5 9 7 3 0 3 .8 1 3 9 5 3 2 .4
5 6 1 5 8 .2 9 8 3 0 8 .2 1 4 0 5 3 9 .0
5 7 1 6 1 .0 9 9 3 1 2 .7 1 4 1 5 4 5 .6
5 8 1 6 3 .9 1 0 0 3 1 7 .2 1 4 2 5 5 2 .3
5 9 1 6 6 .7 1 0 1 3 2 1 .8 1 4 3 5 5 9 .1
6 0 1 6 9 .6 1 0 2 3 2 6 .4 1 4 4 5 6 5 .9
6 1 1 7 2 .6 1 0 3 3 3 1 .0 1 4 5 5 7 2 .8
6 2 1 7 5 .5 1 0 4 3 3 5 .7 1 4 6 5 7 9 .8
6 3 1 7 8 .5 1 0 5 3 4 0 .5 1 4 7 5 8 6 .8
6 4 1 8 1 .6 1 0 6 3 4 5 .3 1 4 8 5 9 3 .8
6 5 1 8 4 .3 1 0 7 3 5 0 .1 1 4 9 6 0 1 .0
6 6 1 8 7 .7 1 0 8 3 5 5 .0 1 5 0 6 0 8 .1
6 7 1 9 0 .9 1 0 9 3 6 0 .0 1 5 1 6 1 5 .4
6 8 1 9 4 .1 1 1 0 3 6 5 .0 1 5 2 6 2 2 .7
6 9 1 9 7 .3 1 1 1 3 7 0 .0 1 5 3 6 3 0 .1
7 0 2 0 0 .6 1 1 2 3 7 5 .1 1 5 4 6 3 7 .5
7 1 2 0 3 .9 1 1 3 3 8 0 .2 1 5 5 6 4 5 .0
7 2 2 0 7 .2 1 1 4 3 8 5 .4
7 3 2 1 0 .6 1 1 5 3 9 0 .7
7 2 2 0 7 .2 1 1 4 3 8 5 .4
7 3 2 1 0 .6 1 1 5 3 9 0 .7
R410A Temperature/Pressure Chart